Collapsible ventilation system

ABSTRACT

A COLLAPSIBLE VENTILATION SYSTEM FOR VENTILATING OR EXHAUSTING AN AIR SPACE WHEREIN THE SYSTEM HAS AN INFLATABLE AND COLLAPSIBLE DUCT SECURED IN COMMUNICATING RELATIONSHIP TO AN EXHAUST DUCT LOCATED ABOVE THE AIR SPACE. A DRUM AND CABLE ARRANGEMENT DRIVEN BY AT LEAST ONE MOTOR IS CONNECTED TO THE LOWER PORTION OF THE INFLATABLE DUCT FOR RAISING AND LOWERING THE DUCT, AND MEANS ARE PROVIDED FOR SUPPLYING AIR TO THE DUCT TO INFLATE IT INTO POSITION. PREFERABLY, HEATED AIR IS USED TO PREVENT UNDESIRABLE CONDENSATION IN THE DUCT WHEN USED IN A RELATIVELY COOLER AMBIENT ATMOSPHERE.

Nov. 9, 1971 J. A. NICHOLS COLLAPSIBLE VENTILATION SYSTEM 2 Sheets-Sheet 1 Filed Aug. 13, 1970 INVENTOR JOHN A; NICHOLS Mnr an, lgndwsolz Wow ATTORNEYS Nov. 9, 1971 J. A. NICHOLS 3,613,509

COLLAPSIBLE VENTILATION SYSTEM Filed Aug. 13, 1970 2 Sheets-Sheet 2 l6 mvnu'ron JOHN A. NICHOLS Emmy/an, fiZnc/arsm 60720500 ATTOR N I'IYS United States Patent 3,618,509 COLLAPSIBLE VENTILATION SYSTEM John A. Nichols, Canton, Mass., assignor to Mill Industries, Inc. Filed Aug. 13, 1970, Ser. No. 63,501 Int. Cl. F23j 11/02 US. Cl. 98-115 13 Claims ABSTRACT OF THE DISCLOSURE A collapsible ventilation system for ventilating or exhausting an air space wherein the system has an inflatable and collapsible duct secured in communicating relationship to an exhaust duct located above the air space. A drum and cable arrangement driven by at least one motor is connected to the lower portion of the inflatable duct for raising and lowering the duct, and means are provided for supplying air to the duct to inflate it into position. Preferably, heated air is used to prevent undesirable condensation in the duct when used in a relatively cooler ambient atmosphere.

The present invention relates to a ventilation system and more particularly to a collapsible ventilation system for ventilating or exhausting an air space.

The use of Fourdrinier machines is an integral step in the process of manufacturing paper, and in operation Fourdrinier machines create large amounts of extremely hot, humid and corrosive air. Because these Fourdrinier machines are frequently located within buildings where other work is being performed which cannot tolerate hot and humid air, and because it is frequently the case that manufacturing or other personnel are located nearby and within the building, it is necessary to exhaust the hot and humid air given off by the Fourdrinier machines as quickly as possible.

Various arrangements and methods for eliminating the hot and humid air have been tried with varying degrees of success; however, the use of exhaust hoods has generally been avoided because of the constant necessity for access to the Fourdrinier machines for repair and replacement, and particularly, for the frequent placement of the wire screen that is used in the manufacture of paper. At least one attempt at the use of a hood incorporated a telescoping hood that telescoped from the front end and over the top of the machine. While this hood arrangement was effective for ventilation it was both cumbersome and extremely costly in construction installation.

In accordance with the present invention an inflatable duct is secured in communicating relationship with a first duct and supported above an air space to be exhausted or ventilated. Means are provided in operative relationship with the inflatable duct for raising and lowering the duct; and means are provided in operative relationship for supplying air, preferably heated, to inflate the inflatable duct when in a lowered position and for enabling deflation of the duct when in a raised position whereby undesirable condensation on the duct is prevented when used in a relatively cooler ambient atmosphere and in its lowered position to pass hot and humid air to or from the air space. Easy access is also provided to the air space when the duct is raised.

Preferably, the inflatable duct includes an exterior wall and an interior wall spaced apart to form an air pocket and air supplying and deflation means are in communication with the air pocket. It is also preferred that a substantially rigid and endless tube be attached to the lower ends of the exterior and interior walls to define a lower open end of the inflatable duct through which the ventilating or exhausting air passes. Additionally, it is pre- Patented Nov. 9, 1971 ferred that the rigid tube be coupled to the raising and lowering means and that the rigid tube include at least one hollow, tubular and inflated member. The rigid tube is preferably formed of a plurality of sections of hollow, tubular and inflated members coupled together, and it is also preferred that the inflatable duct be comprised of plastic material for enabling operation of the duct system at air temperatures at least as great as 200 F.

In accordance with a preferred embodiment, the inflatable duct widens at the lower end to form a hood and the air deflation means include a plurality of connections in communication with the air pocket to selectively enable escape of air therefrom when the inflatable duct is at least partially collapsed. It may also be desirable for the hood to include sections comprised of a thickness of clear plastic to permit observation of the interior of the hood and of the machinery or areas below the hood. The raising and lowering means preferably include a motor; a shaft coupled to be driven by the motor; two cable drums connected to rotate with the shaft and two cables respectively connecting the inflatable duct to the cable drums whereby rotation of the shaft in a first direction raises the inflatable duct member and rotation of the shaft in a second direction lowers the inflatable duct member. Of course, when a long hood is used a number of such motors, shafts and drums may be required.

Preferably, the process for exhausting air from the air space in accordance with the invention comprises the steps of placing the collapsible duct, having an inflatable air pocket therein, in contiguous relationship With the air space to be exhausted or ventilated; inflating the air pocket with air heated to a temperature higher than the temperature of the surrounding ambient air; and creating a suction within the inflatable duct and without the air pocket to ventilate or exhaust the hot and humid air to or from the air space through the inflatable duct whereby undesirable condensation on the duct is prevented because of the heated air within the air pocket.

Thus, the present invention provides the advantageous features of being easily and quickly drawn up and out of the way for ready access to Fourdrinier machines or other machinery and also provides an inflatable and collapsible duct which may be inflated by heated air so as to avoid undesirable condensation on the inflatable duct when used in a relatively cooler ambient atmosphere to exhaust hot and humid air.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention. The accompanying drawings illustrate an example of a preferred embodiment of the invention and together with the description serve to explain the principles of the invention.

-FIG. 1 is a diagrammatic view, partly in section, of a preferred embodiment of the invention; and

FIG. 2 is a front elevation of the preferred embodiment illustrated in FIG. 1.

With reference now to the drawings, wherein like characters designate like or corresponding parts throughout the several views, there is shown in FIGS. 1 and 2 a first duct 10, which is supported by a structure 12 in position above an air space 14 to be ventilated or exhausted. As here illustrated and described, the air space 14 is adjacent to a Fourdrinier machine 16; however, it should be understood that the duct system of this invention can be used for ventilating or exhausting air or other gases to or from any desired air space.

An inflatable and collapsible duct 18 is secured by conventional means in communicating relationship to first duct 10. As here embodied, the inflatable duct has an exterior flexible wall 20 and an interior flexible wall 22 spaced from the exterior wall to form an air pocket 24.

Means are also provided in operative relationship for supplying heated air to inflate duct 18 and for enabling deflation of the inflatable duct. As here embodied, the air supplying and deflation means may include only a coupling member 26, which is in communicating relationship with air pocket 24 and which may be selectively coupled to an air supply (not shown) when inflation is desired or vented to the atmosphere when deflation of duct 18 is desired. An alternative embodiment of the air supplying and deflation means provides coupling 26 as the air supplying means, and in addition, provides one or more deflation coupling 28, 28', etc. Whereby air can be selectively suppled to air pocket 24 via coupling 26 and whereby the air can be exhausted from air pocket 24 via couplings 28 and 28.

'Means are also provided in operative relationship for raising and lowering inflatable duct 18 to enable easy and quick access to the machinery 16 or to the air space 14. Raising duct 18 also permits passage of traveling cranes 29 or other equipment through the area occupied by the inflatable duct when in its lowered and inflated position. As here embodied, the raising and lowering means include a motor 30, a shaft 32 coupled to be driven by the motor, and two cable drums 34 and 34', respectively connecting the inflatable duct to the cable drums via cables 36 and 36' whereby rotation of shaft 32 in a first direction raises the duct 18 and rotation of the shaft 32 in a second direction lowers the inflatable duct.

A substantially rigid and endless tube 38 is attached to the lower ends of the exterior and interior walls 20 and 22 of the duct 18, and this rigid tube defines a lower open end of the inflatable duct through which the ventilating or exhausting air or other gases pass. As here embodied, the rigid tube 38 is coupled to cables 36 and 36 via conventional fastening members 40 and 40', and the rigid tube includes one or more hollow, tubular and permanently inflated sections, 38, 38", etc., that are conventionally coupled together as illustrated in FIG. 2. In addition, the preferred embodiment of the invention provides for a hood 42 which widens the inflatable duct at the lower end thereof.

Preferably, the inflatable duct is comprised of plastic material which is capable of enabling operation of the duct system at air temperatures at least as great as 200 F. In addition, it may be desirable to form sections of the hood 42 of a thickness or thicknesses of clear plastic 50 to permit observation of the interior of the hood and of areas below the hood and adjacent machinery 16.

In operation, inflatable duct 18 is lowered by operation of motor 30 and by the corresponding rotation of cable drums 34 and 34' to any desired position between the ducts lowest position, shown in FIG. 1, and its highest position, shown in phantom in FIG. 1. In the example of FIG. 1, the inflatable duct is placed in contiguous relationship with air space 14 immediately adjacent to Fourdrinier machine 16. During or after positioning of the inflatable duct, air is supplied through coupling 26 to pressurize air pocket 24. Where hot and humid air is being passed through inflatable duct 18 in the presence of cool or ambient air, air heated to a temperature above that of the ambient air is passed into air pocket 24 so that undesirable condensation on the inflatable duct is prevented. With hood 42 in place and with inflatable duct 18 properly inflated with heated air, a fan 52 mounted within duct and driven by motor 54 is operated to create a suction within the inflatable duct so as to exhaust hot and humid air from the air space 14. Although the operation of the invention has been described with respect to exhausting hot and humid air from air space it should be understood that this invention is also equally applicable when used to ventilate an air space or to force air into an air space.

When machine 16 requires repair or wise necessary to obtain access to the machine,

when it is othersuch as for replacement of the wire screen in a Fourdrinier machine, motor 30 is again energized to drive shaft 32 in a direction opposite to that which caused the lowering of hood 42. As a result, cables 36 and 36 are wound on the respective cable drums 34 and 34' and hood 42 and inflatable duct 18 are at least partially collapsed. Simultaneously, the exhaust connections 28 and 28 are opened and coupling 26 may be vented to the atmosphere so that the air located within air pocket 24 is exhausted to the atmosphere to facilitate collapse of the inflatable duct as it is raised.

Thus, the present invention provides a simple, inexpensive, and easily operable collapsible duct system whereby hot and humid air can be exhausted from an air space without the problems of condensation on the ducts and wherein a duct is collapsible to facilitate raising of the duct up and away from the air space so that other machinery, such as cranes, can be passed through or over the air space when desired.

The invention in its broader aspects is not limited to the specific details shown and described and departures may be made from such details without departing from the principles of the invention and without sacrificing its chief advantages.

What is claimed is:

1. A collapsible duct system for ventilating or exhausting an air space, comprising:

a first duct supported above said air space;

an inflatable and collapsible duct secured in communicating relationship to said first duct;

means in operative relationship for raising and lowering said inflatable duct; and

means in fluid communication for supplying air to inflate said inflatable duct and for enabling deflation of said inflatable duct.

2. A collapsible duct system as in claim 1 wherein said inflatable duct includes an exterior flexible wall and an interior flexible wall spaced apart to form an air pocket and wherein said air supplying and deflation means are in fluid communication with said air pocket.

3. A collapsible duct system as in claim 2 further including a substantially rigid, endless tube attached to the lower ends of said exterior and interior walls and defining a lower open end of said inflatable duct through which said ventilating or exhausting air passes.

4. A collapsible duct system as in claim 3 wherein said rigid tube is coupled to said raising and lowering means.

5. A collapsible duct system as in claim 4 wherein said rigid tube includes at least one hollow, tubular, and permanently inflated member.

6. A collapsible duct system as in claim 4 wherein said rigid tube includes a plurality of sections of hollow, tubular and inflated members coupled together.

7. A collapsible duct system as in claim 6 wherein said inflatable duct is comprised of plastic material enabling operation of said duct system at air temperatures at least as great as 200 F.

8. A collapsible duct system as in claim 7 wherein said inflatable duct widens at the lower end thereof to form a hood.

9. A collapsible duct system as in claim 8 wherein said air deflation means include a plurality of connections in communication with said air pocket for selectively enabling escape of air therefrom.

10. A collapsible duct system as in claim 9 wherein said hood includes sections comprised of clear plastic to permit observation of the interior of said hood and of areas below said hood.

11. A collapsible duct system as in claim 1 wherein said raising and lowering means include:

a motor;

a shaft coupled to be driven by said motor;

two cable drums connected to rotate with said shaft;

and

two cables respectively connecting said inflatable duct creating a pressure diflerential within said inflatable to said cable drums, whereby rotation of said shaft duct and without said air pocket to exhaust said hot in a first direction raises the inflatable duct and roand humid air from said air space through said intation of said shaft in a second direction lowers the flatable, duct whereby undesirable condensation on inflatable duct. 5 said inflatable duct is prevented by use of said heated 12. A collapsible duct system as in claim 1 in combinaair within said air pocket. tion with a fan in communication with said first duct for directing air downwardly or upwardly through said in- References Cited g i f h f f UNITED STATES PATENTS process or ex ausing a1r rom an air space, 10 which air is hot and humid with respect to surrounding g; BDlckmson ambient air, comprising the steps of: arton h placing a collapsible duct having an inflatable air pocket therein in contiguous relationship with said air space; EDWARD MICHAEL Pnmary Examlner inflating said air pocket with air heated to a tempera- 15 U S C1 ture higher than the temperature of said surrounding 1 11 ambient air; and 38 9 

